Valve-centering device



Dec p23, 1930. H. G. MILLER 1,786,023 I VALVE CENTERING DEVICE FiledApril 27, 1927 INVENTOR. Ham/ 51 Mu 00 404 A TTORNEYS.

Patented Dec. 23, 1930 UNITED STATES HARRY G. LIILLER, OF DENVER,COLORADO VALVE-CENTERING DEVICE 7 Application filed April 27,

This inventionrelates to improvements in stem centering means for valvegrinding machines and has particular reference to means closed acarriage for stemmed valves provided with a tail stock centering pin andan intermediate steady rest adapted to co-operate in centering thevalvestem independently of the valve the latter .beingengaged by a drivinghead primarily for the purpose of rotating it about the axis of thestem. In the practical use of suchmachines, it has been found thatvalve, stems frequently have irregularities of surface contour due insome cases to original defects, in other cases to wear, and in othercases to an accumulation of carbon, and where such irregularitiesregister with the steady rest, it is obvious that defective alignment oreccentricity in rotation will result. The steady rest is necessarilylocated in proximity to the valve and therefore such irregularitiesinterfere materially with the accomplishment ofthe de sired purpose ofgrinding the valve true to the axis of its stem.

It has also been found difficult to; avoid movement of the valve stemwith reference to the steady rest, thereby permitting a vibratory orchattering movement of the valve or a displacement of the valve and theassociated end portion of the stem under frictional pressures exerted onthe face of the valve by the abrading tool or grinding wheel.

The primary ob ect of my invention is to provide means for supportlngvalves true to the axes of their stems while such valves and stems arebeing rotated during a grinding operation regardless of whether thevalve stems are carbon1zed,-worn, or otherw se provided with surfaceirregularities or eccentric depressions.

More particularly stated, the object ofthis invention-is to provide asleeve mounting into which the valve stem may beinserted in. such amanner that the axis o-f the stem and mount- 1927. Serial No. 186,952.

ing will coincide,the mounting being provided with a cylindrical surfacetruly concentric to the axis of the stem and journalled in a bearingmember adapted for anchoring engagement with the steady rest, wherebythe valve stem and its sleeve mounting may be rotated in such bearingduring a valve grinding operation, thereby insuring a grinding of thevalve true to the axis of the mounting and, therefore, also true to theaxis of the stem.

In the drawings Figure 1 shows a fragment of a grinding machine carriageprovided with head and tail stock members and an intermediate steadyrest, all similar to the corresponding parts disclosed in said formerapplication but with the valve stem supported in the improved mountingforming the subject matter of this application.

Figure 2 is a cross sectional View drawn on line 22 of Figure 1.

Figure 3 is a longitudinal sectional view of the mounting drawn on aplane intersecting the oil cup of the anchoring bearing member and theset screw for securing the mounting rigidly to the valve stempreparatory to the grinding operation, a fragment of the steady restbeing also illustrated in section, and a tappet valve being illustratedin full.

Like parts are identified by the said reference characters throughoutthe several views. A hearing sleeve 10 having an outwardly turned endflange 11 is journalled in a bearing member 12, one end of which abutsthe flange 11 and the other end of which is provided with acylindrically enlarged portion 13 having a conically tapered undercutshoulder 1e adapted to receive the correspondingly tapered surface 15 ofa semi-cylindrical steady rest socket member 16 supported from thecarriage rod 17 by the bracket. arm 18 shown in Figure l. The oil cup 19is. preferably employed to feed lubricant into; the

longitudinal channel 20 formed in the outer surface of the bearin sleeve10 as clearly shown in Figure 3. g

The lubricant in the channel 20 also lubri- G t s the n l h t be ring ofhe l e 23 against-the portion 13 of-the. bearing meniher 12. Therefore,the sleeve 23 has little tendency to rotate the bearing member 12 andthe anchorage of the conical projection 15 is effective to hold thebearing member against rotation being in substantially cone clutchengagement therewith by reason of entry of the projection 15 in theconically tapered groove 1 1.

A. co-operating valve stem mounting sleeve 22 is secured to the bearingsleeve 10 by a coupling sleeve 23. A set screw 2st connects the couplingsleeve with the mounting sleeve 22 and this set screw is also utilizedto lock the valve stem 25 in the mounting preparatory to the grindingoperation.

The object of forming the mounting sleeves 10 and 22 in two partsinstead of one is to facilitate tempering them without the distortionwhich might result from tempering a tube aaving a length equal to thecombined length of the sleeves 10 and 22.

The forward end 27 of the coupling sleeve abuts the portion 13 of theanchoringbearing member 12 when the parts are assembled in the carriagepreparatory to a grinding operation. The tail stock centering pin 28 isprovided with a centering cup 29 having a conically tapered socket toreceive the tapered end 3O the mounting sleeve 22. The outer end of thecentering pin 28 is provided with a cam 32 adapted to bear against thetail stock head 33 to retract the centering pin, said pin being normallyurged inwardly by spring 341 in the ordinary manner.

In preparation for grinding a valve the stem 25 will first be insertedin the bearing sleeve and rotated therein whenever deposits of carbon orother projecting material tend to interfere with the movement of thestem through this sleeve. In this manner deposits of carbon such asaccumulate upon the stems of internal combustion engine valves near thevalve heads may be utilized to fill depressions and insure a tight fitof this portion of the stem within the sleeve 10. Thereupon the mountingsleeve 22 will also be applied to the stem, the coupling sleeve servingto properly align the two sleeves 10 and 22 and the set screw 24. beingthen turned up to securely anchor the mounting sleeve to the valve stem,whereupon the outer or left hand end of the sleeve 22 may be engaged inthe tail stock centering cup 29 and the centering pin 28 pushedbackwardly until the portion 13 of the bearing 12 can be brought into aposition for engagement with the conically tapered end of the steadyrest socket member 16. The anchorage obtained by the surface 15 of thesteady rest in the conically undercut groove 14; of the portion 13 ofthe bearing securely anchors this hearing to the steady rest so that thebearing becomes temporarily a part of the steady rest within which thevalve stem and its bearing sleeve 10 may rotate. The

pressure of the tail stock spring 34: brings the forward end of thecoupling sleeve 23 into thrust bearing contact with the portion 13 olthe bearing member 12, thereby holding this portion in anchoringrelation to the steady rest socket member 16, all. other parts or themounting being free to rotate when the valve is being rotated in contactwith the grinding wheel by the driving head 36, the latter ha ving awork engaging chuck 37, which, for the purpose of this description, maybe assumed to be of any ordinary construction.

The set screw 24 may be utilized to permit an adjustment of the mountingrelatively to the valve stem so as to ensure that the valve is in properposition to be engaged by the driving head and a slight permissibleseparation of the end 27 of the coupling sleeve 23 from the portion 13of the non-rotatable hearing member 12 will allow the spring 34 to pressthe valve resiliently against the driving head. This or any othersliding interlocking connection of the non-rotatable hearing member withthe steady rest will allow the valve to be pushed against the drivinghead with the desired pressure.

I claim:

1. In a grinding machine carriage provided with head and tail stockmembers for engaging stemmed valves, a centering mounting for the valvestems provided with a nonrotative bearing member near one end in whichsuch mounting is journalled, said hearing member having means formanipulative anchoring engagement with a steady rest on the carriage; incombination with a steady rest adapted to permit free removal of thebearing member when the latter is in a position of manual adjustmentrelative to the steady rest.

2. In a grinding machine carriage provided with head and tail stockmembers for engaging stemmed valves, a centering mounting for the valvestems provided with a nonrotative bearing member near one end in whichsuch mounting is journalled, said bearing member having means foranchoring engagement with a steady rest on the ca rriage said mountinghaving a portion for engagement with a tail stock centering pin andanother portion adapted for thrust beau ing engagement with thenon-rotative bean ing member.

3. A centering mounting for valve stems comprising a stem support inwhich a valve stem may be centered and secured and a bearing in whichthe stem support may rotate, said bearing having means for anchorinengagement with an open steady rest.

4. A centering mounting for valve stems comprising a stem support inwhich a valve stem may be centered and secured and a bear ing in whichthe stem support may rotate, said bearing having means for anchoringengagement with an open steady rest, and said stem. support beingadapted for engagement with a tail stock centering pin, and of a lengthto span the space between said pin and the steady rest, whereby said pinmay hold the bearing in said interlocking anchoring engagenient.

5. The combination with the carriage of a valve grinding machine, of acentering mounting for valve stems, comprising a valve stem holder)rovided with a cylindrical bear ing surface concentric: to the axis ofthe stem to be engaged by the holder wheniproperly secured therein, abearing sleeve in which one end of the holder is journaled, and a steadyrest having a relatively fixed open bearing for the bearing sleeve, saidsleeve and steady rest being formed for manipulative interlockingengagement to prevent the sleeve from moving out of the steady rest onthe open side.

6. The combination with the carriage 01" a valve grinding machine, of acentering mounting for valve stems, comprising a valve stem holderprovided with a cylindrical hearing surface concentric to the axis ofthe stem to be engaged by the holder when properly secured therein, abearing sleeve embracing said cylindrical bearing surface and shoulderedfor interlocking thrust bearing engagement with a relatively fixedsupport, a rela tively fixed steady rest having an'open hearing toreceive said sleeve, and against which said sleeve shoulder may havethrust engagement, and a. resiliently mounted tail stock centering pinformed to engage the outer end of the holder to center the latter inco-operation with said steady rest, and to press the same into thrustbearing relation to the end of the sleeve, said sleeve being formed toutilize said pressure to anchor it to the steady rest.

7. The combination with a valve grinding machine carriage having a headstock, tail stock, and an intermediate open steady rest, of a mountingfor valve stems adapted to hold the stem with its axis coinciding withthat of the mounting, means carried by the tail stool; for centering themounting upon said axis at its outer end, and means carried by thesteady rest for centering the inner end portion of the mounting, andholding it to such centered position during rotation of the mounting ina valve grinding operation.

8. The combination with a valve grinding machine carriage having a headstock, a tail stock, and an intermediate open steady rest, of acylindrical mounting within which valve stems may be anchored with theiraxes coincident with the axis of the mounting, a bearing sleeve for oneend portion of the mounting adapted to be received in the open st adyrest, and means for anchoring the sleeve to the steady rest bythrustengagement with one side of the latter, said mounting beingadapted to receive thrust from the tail stock centering means, and totransm t HARRY G. MILLER.

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